United Kingdom

The highland zone of England and Wales consists, from north to south, of four broad upland masses: the Pennines, the Cumbrian Mountains, the Cambrian Mountains, and the South West Peninsula. The Pennines are usually considered to end in the north at the River Tyne gap, but the surface features of several hills in Northumberland are in many ways similar to those of the northern Pennines. The general surface of the asymmetrically arched backbone (anticline) of the Pennines is remarkably smooth because many of the valleys, though deep, occupy such a small portion of the total area that the windswept moorland between them appears almost featureless. This is particularly true of the landscape around Alston, in Cumbria (Cumberland), which—cut off by faults on its north, west, and south sides—stands out as an almost rectangular block of high moorland plateau with isolated peaks (known to geographers as monadnocks) rising up above it. Farther south, deep and scenic dales (valleys) dissect the Pennine plateau. The dales’ craggy sides are formed of millstone grit, and beneath them flow streams stepped by waterfalls. The most southerly part of the Pennines is a grassy upland. More than 2,000 feet (610 metres) above sea level in places, it is characterized by the dry valleys, steep-sided gorges, and underground streams and caverns of a limestone drainage system rather than the bleak moorland that might be expected at this elevation. At lower levels the larger dales are more richly wooded, and the trees stand out against a background of rugged cliffs of white-gray rocks. On both Pennine flanks, older rocks disappear beneath younger layers, and the uplands merge into flanking coastal lowlands.

The Cumbrian Mountains, which include the famous Lake District celebrated in poetry by William Wordsworth and the other Lake poets, constitute an isolated, compact mountain group to the west of the northern Pennines. Many deep gorges, separated by narrow ridges and sharp peaks, characterize the northern Cumbrian Mountains, which consist of tough slate rock. Greater expanses of level upland, formed from thick beds of lava and the ash thrown out by ancient volcanoes, lie to the south. The volcanic belt is largely an irregular upland traversed by deep, narrow valleys, and it includes England’s highest point, Scafell Pike, with an elevation of 3,210 feet (978 metres), and Helvellyn, at 3,116 feet (950 metres). Nine rivers flowing out in all directions from the centre of this uplifted dome form a classic radial drainage pattern. The valleys, often containing long, narrow lakes, have been widened to a U shape by glacial action, which has also etched corries from the mountainsides and deposited the debris in moraines. Glacial action also created a number of “hanging valleys” by truncating former tributary valleys.

Mountain-encircled Esthwaite Water in the Lake District of northwestern England.Tom Wright/FPG

The Cambrian Mountains, which form the core of Wales, are clearly defined by the sea except on the eastern side, where a sharp break of slope often marks the transition to the English lowlands. Cycles of erosion have repeatedly worn down the ancient and austere surfaces. Many topographic features derive from glacial processes, and some of the most striking scenery stems largely from former volcanism. The mountain areas above 2,000 feet (610 metres) are most extensive in North Wales. These include Snowdonia—named for Snowdon (Yr Wyddfa), the highest point in Wales, with an elevation of 3,560 feet (1,085 metres)—and its southeastern extensions, Cader Idris and Berwyn. With the exception of Plynlimon and the Radnor Forest, central Wales lacks similar high areas, but the monadnocks of South Wales—notably the Black Mountains and the Brecon Beacons—stand out in solitary splendour above the upland surfaces. There are three such surfaces: a high plateau of 1,700 to 1,800 feet (520 to 550 metres); a middle peneplain, or worn-down surface, of 1,200 to 1,600 feet (370 to 490 metres); and a low peneplain of 700 to 1,100 feet (210 to 340 metres). These smooth, rounded, grass-covered moorlands present a remarkably even skyline. Below 700 feet (210 metres) lies a further series of former wave-cut surfaces. Several valleys radiate from the highland core to the coastal regions. In the west these lowlands have provided a haven for traditional Welsh culture, but the deeply penetrating eastern valleys have channeled English culture into the highland. A more extensive lowland—physically and structurally an extension of the English lowlands—borders the Bristol Channel in the southeast. The irregularities of the 600-mile (970-km) Welsh coast show differing adjustments to the pounding attack of the sea.

Coastline, Pembrokeshire Coast National Park, Wales.James P. Rowan